A 42-year-old woman from Delhi presents with a 6-month history of progressive mid-back pain and bilateral lower limb weakness. On examination, she has a visible kyphotic deformity and paraplegia (ASIA Grade B). Imaging shows destruction of T8–T9 vertebral bodies with anterior subluxation, severe kyphosis (70°), and cord atrophy on MRI. She has completed 9 months of anti-tuberculous therapy with no improvement in neurological status. What is the most likely mechanism of her neurological deficit at this stage?